Sean,
CPS can be tested with a ohm meter to determine if good. Same for the RPM
sensor.
Would imagine the Indy shop will figure it out. These cars are not really
that complicated, that is, if you know what you're doing! You can test
almost everything, (excepting ECU) but really needs to be someone familiar
with the electronics in these...
Did they even bother to pull codes? 12 hours diagnosing! Sounds a little
"hinky" to me!
good Luck!
Eric